The fields/states to include in the step are defined through the property segvar. The property segvarspec controls which components of the fields/states in segvar to include in the step. By default segvarspec is all, in which case all components in the fields/states of segvar are included. By setting segvarspec to manual, a subset of the fields/states of segvar can be included in the step. The components to include in the step are then defined through the property segcomp.

Analogously, the property subterm controls how each substep is terminated through the properties maxsubiter, subiter, and subntol/subntolfact for a stationary or time-dependent problem.

The damping technique used in each substep is controlled by the property subdtech. The default setting is const, which means that damped Newton iterations with a fixed damping factor is used. The damping factor is set in the property subdamp. The other available damping technique is autodamp in which case the damping factor is automatically adjusted. For substeps which uses autodamp, four other properties are supported: subhnlin, subinitstep, subminstep, and subrstep. For each substep, these properties set the properties hnlin, initstep, minstep, and rstep supported by the nonlinear solver, see FullyCoupled.

In substeps with subdtech=const, the property subjtech controls how often the Jacobian is updated. The values minimal, once, and onevery give the same Jacobian update techniques as they do when applied to the coupled solver through the property jtech; see FullyCoupled. The value onfirst makes the solver update the Jacobian of the substep on the first subiteration each time the substep is solved for. Default value is onevery for stationary problems and minimal for time-dependent problems.

When subdtech is set to ddog (stationary problems), the double dogleg solver is used. The initial damping factor is controlled by the property subddoginitdamp and the property subresscale controls the residual scaling. The option resscale=scalefieldwise scales the equations based on the field-wise sizes of the initial residual. When the option subresscale=scaleuniform is selected the algorithm terminates on the relative residual based on the initial residual.

The property subtermonres controls the termination criterion for stationary problems when segterm is not iter. When subtermonres=off the estimated error is solution-based, with subtermonres=on it is based on a relative residual, and for subtermonres=auto the estimated error is the minimum of the solution and residual based errors. For subtermonres=auto the property subreserrfact is a scalar factor multiplying the relative residual error.